Vestibular function testing confirms a greater incidence of peripheral vestibular hypofunction in service members who experience dizziness with blast-related brain injury (TBI) relative to those who are asymptomatic, say authors of an article published online ahead of print February 24 in Otology & Neurology. Additionally, oculomotor abnormalities and/or nystagmus consistent with central involvement were present in 10 of the 24 study participants tested. The precise cause of these findings remains unknown, the authors add.

This prospective, nonblinded, nonrandomized descriptive study conducted at a tertiary care facility within the Department of Defense Medical Center included 24 service members recovering from blast-related TBI sustained in Iraq or Afghanistan.

Vestibular testing confirmed a greater incidence of vestibular and oculomotor dysfunction in symptomatic (vestibular-like dizziness) personnel with blast-related TBI relative to asymptomatic group members. Videonystagmography in the symptomatic group revealed abnormal nystagmus or oculomotor findings in 6 of 12 subjects tested. Similarly, rotational chair testing in this group revealed evidence of both peripheral (4/12) and central (2/12) vestibular pathology. By contrast, the asymptomatic group revealed less vestibular impairment with 1 of 10 rotational chair abnormalities. The asymptomatic group was further characterized by fewer aberrant nystagmus findings (4/12 abnormal VNGs). Computerized dynamic posturography testing revealed no significant differences between groups. Self-report measures demonstrated differences between groups.

APTA member Matthew R. Scherer, PT, PhD, NCS, led this study, which was coauthored by Michael C. Schubert, PT, PhD, who also is an association member.